<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>超链接</title>
		<style>
			a{
				display: block;/* margin不只有横向 */
				text-decoration: none;
				line-height: 50px; 
				width: 200px;
				height: 50px;
				padding: 10px;
				margin: 10px; /* 只有横向 */
			}
			a:link{
				color: yellow;
			}
			a:visited{
				color: red;
			}
			a:hover{
				color: green;
			}
			a:active{
				color: blue;
			}
		</style>
	</head>
	<body>
		<a href=" ">百度一下</a>
	</body>
</html>
